Seating apparatus

ABSTRACT

Aspects of the present invention relate to a seat cushion (1) including a compressible member (15) and at least one insert (16). The insert (16) has one or more inflatable bladders (17-n). The at least one insert (16) is at least partially encapsulated within the compressible member (15). Further aspects of the present invention relate to a method of forming a seat cushion (1); a seat assembly (2) and a vehicle (V).

TECHNICAL FIELD

The present disclosure relates to a seating apparatus. Aspects of theinvention relate to a seat cushion, a vehicle seat assembly, an insert,a vehicle and a method of forming a compressible member.

BACKGROUND

It is known to provide a vehicle seat with a variety of ways ofadjustment to enable occupant comfort. For example, a vehicle seat maybe provided with a pneumatic bladder to give adjustable support. Thepneumatic bladder may be positioned underneath or on top of the seatfoam. Most commonly these pneumatic bladders are found in the seat backto provide lower back (lumbar) support but they are known to have beenused in the cushion region to support the body of the seated occupant.Lumbar support is often both height and depth adjustable. The firmnessof the seat foam is specified as a result of two main factors, thevehicle ride aspiration (where the occupant needs to be seated inrelation to the vehicle design) and for safety for homologation (legalcertification), which requires the occupant to be in a predefinedlocation. Conventional pneumatic bladders used in seats have a singlechamber and inflate uniformly. This means conventional pneumaticbladders exert a force in all directions resulting in variations in theseat properties. Furthermore, a known vehicle seat typically comprises aseat back and a seat base. The vehicle seat may comprise one or moreseat cushions each being upholstered with a respective seat cover. Seatcovers of the seat assembly may be prone to sag due to a reduction inthe tautness of the seat cover. The sag may be a result of stretching ordeformation of the seat cover, for example due to repeated or prolongeduse. Alternatively, or in addition, sag may be caused by deformation ofa compressible member in the seat cushion, for example due to localisedor repeat loading. The appearance of the vehicle seat may be adverselyaffected as a result of sag of the seat cover. It is an aim of thepresent invention to address one or more of the disadvantages associatedwith the prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a seat cushion, avehicle seat assembly, an insert, a vehicle, and a method of forming acompressible member as claimed in the appended claims.

According to an aspect of the present invention there is provided a seatcushion comprising: a compressible member; and at least one insertcomprising one or more inflatable bladders; wherein the at least oneinsert is at least partially encapsulated within the compressiblemember. The or each inflatable bladder is disposed at least partiallywithin the compressible member. At least in certain embodiments, the oreach inflatable bladder is partially or completely encapsulated withinthe compressible member. The one or more inflatable bladders can beinflated to controllably adjust one or more properties of the seatcushion, for example to adjust a firmness or a hardness of the seatcushion. When inflated the one or more inflatable bladders expand andmay compress the surrounding region of the compressible member which atleast partially encapsulates the inflatable bladder. This compressionmay reduce compliance of the compressible member and creates a harder(firmer) condition for the seat occupant. The one or more inflatablebladders may be installed in capillaries formed in the foam; or the oneor more bladders may be moulded into the compressible member duringfabrication. The or each inflatable bladder may be spaced apart from anouter surface of the compressible member.

At least in certain embodiments, the behavioural properties of the seatcushion can be adjusted by varying an inflation pressure of the one ormore inflatable bladders. The inflation pressure may be adjusted by theuser to improve comfort. The seat cushion may be an adaptive seat forstiffness and/or hardness.

The one or more inflatable bladders may be configured to inflatepredominantly (or exclusively) in a single axis. For example, the oreach inflatable bladders may be configured such that the inflationprimarily increases the depth of the inflatable bladder. The or eachinflatable bladder may have a multi-cell arrangement, for examplecomposed of an upper cavity and a lower cavity. The cells in themulti-cell arrangement may be in fluid communication with each other.More than one bladder may be installed within the compressible member,for example to extend under a main occupant contact area of the seatcushion. When inflated, the or each inflatable bladder compresses thecompressible member (nominally in a vertical axis) effectivelyincreasing the local density of the foam where the bladder interfacesthe foam. This may increase the hardness or firmness of the seatcushion. Since each bladder is installed within foam and the loadabsorption of the foam is maintained, at least in certain embodimentsthe effective foam (comfort) depth may not be reduced. The one or moreinflatable bladders may be arranged longitudinally within the seat foam.Alternatively, or in addition, the one or more inflatable bladders maybe arranged laterally. The or each inflatable bladder may comprise oneor more elongated sections. The or each inflatable bladder mayoptionally comprise a plurality of the elongated sections. The elongatedsections may extend substantially parallel to each other. The at leastone inflatable bladder may be co-moulded with the compressible member.

The seat cushion may be provided in a seat base or a seat back. The seatcushion may be provided in a leg support, such as a calf support.Alternatively, or in addition, the seat cushion may be incorporated intoa lateral support, such as a lumbar support.

The compressible member may comprise at least one chamber associatedwith the or each inflatable bladder. The at least one chamber may beconfigured to accommodate expansion of at least part of the associatedinflatable bladder. The at least one chamber may be pre-formed withinthe compressible member. The at least one chamber may, for example, beformed when the compressible member is moulded. The at least one chambermay be formed concurrent with the at least partial encapsulation of theat least one insert. The or each chamber may form an expansion chamberinto which the or each inflatable bladder can expand. The chamber can beprofiled to control expansion of the inflatable bladder, for example tocontrol a direction and/or an extent of the expansion of the or eachinflatable bladder. The or each chamber and the associated inflatablebladder may have complementary profiles when the bladder is inflated.

The insert may comprise at least one support element for cooperatingwith a support arm to support the insert during a moulding operation.The at least one support element may be disposed adjacent to theinflatable bladder. The at least one support element may be configuredto form the at least one chamber in the compressible member. The atleast one support element and the inflatable bladder may have at leastsubstantially the same profile. The at least one support element may bedeformable. The at least one support element may comprise a sleeve. Theor each support element may form a pocket. The pocket may be configuredto receive a support arm for supporting the insert. The pocket may beopen at a first end and/or a second end. The support element may bedisposed adjacent to the inflatable bladder.

The or each insert may comprise a first inflatable bladder and a secondinflatable bladder. The first and second inflatable bladders may beinflatable together or independently of each other. The first inflatablebladder and the second inflatable bladder may be in fluid communicationwith each other. Alternatively, the first inflatable bladder and thesecond inflatable bladder may not be fluid communication with eachother. The first inflatable bladder may be disposed at a proximal end ofthe insert. The second inflatable bladder is disposed at a distal end ofthe insert.

The seat cushion may comprise a first port in fluid communication withthe first inflatable bladder; and a second port in fluid communicationwith the second inflatable bladder. The first port and second port maybe provided in a manifold for connection to a supply line for supplyinga pressurised fluid, such as air. The supply line may be connected to apressurised air supply for supplying air to inflate the at least oneinflatable bladder. The pressurised air supply may comprise a compressorand/or a reservoir. The first and second ports may be disposed at afirst end of the insert.

The seat cushion may comprise a first inflatable bladder disposed in afirst lateral position; and a second inflatable bladder disposed in asecond lateral position. Alternatively, or in addition, the seat cushionmay comprise a first inflatable bladder disposed in a front position;and a second inflatable bladder disposed in a rear position.

According to a further aspect of the present invention there is provideda vehicle seat assembly comprising one or more seat cushions asdescribed herein. The seat cushion described herein may be incorporatedinto a seat base or a seat back. Alternatively, or in addition, the oneor more seat cushion may provide a supplementary support. For example,the seat cushion may comprise a lumbar support, a thigh support or a legsupport.

The vehicle seat assembly may be operable to implement a first controlfunction comprising: a first cycle comprising inflating and deflatingthe first inflatable bladder; and a second cycle comprising inflatingand deflating the second inflatable bladder. The first and second cyclesmay be controlled to induce a cyclical motion about a first axis. Thecyclical motion about the first axis may be suitable for massaging aseat occupant. The first and second cycles may be out of phase with eachother. The seat cushion may be disposed in a base of the vehicle seatassembly. The first axis may be a longitudinal axis. The inducedcyclical motion may comprise a rolling hip motion. A control system maycontrol the inflation and deflation of the first and second inflatablebladders. The vehicle seat assembly may be operable to implement asecond control function comprising: a third cycle comprising inflatingand deflating the first inflatable bladder; and a fourth cyclecomprising inflating and deflating the second inflatable bladder. Thethird and fourth cycles may be controlled to induce a cyclical motionabout a second axis. The cyclical motion about the first axis may besuitable for massaging a seat occupant. The third and fourth cycles maybe in phase with each other. The second axis may be a transverse axis.The induced cyclical motion may comprise a pitching hip motion. Acontrol system may control the inflation and deflation of the third andfourth inflatable bladders. At least in certain embodiments, the firstcontrol function and/or the second control function may provide ananti-fatigue function. The first control function and/or the secondcontrol function may induce a rhythmic motion of the hips and/or spineof the occupant which is representative of the motion occurring when aperson is walking. The first control function and/or the second controlfunction may have an operating frequency of 20 to 100 cycles per minute,more particularly 30 to 70 cycles per minute, for example 50 cycles perminute. It is believed that this may enhance spinal lubrication and/orincrease blood flow compared to a static posture.

The vehicle seat assembly may be configured to reduce the inflationpressure when an occupant sits on the seat cushion. The controlledreduction in the inflation pressure may provide a seat welcome featureon initial sit-in via the relaxing effect of the partial or completedeflation of the first and second inflatable bladders.

According to a further aspect of the present invention there is providedan insert for encapsulation at least partially within a compressiblemember, the insert comprising: at least one inflatable bladder; and atleast one support element for cooperating with a support arm to supportthe insert during a moulding operation.

The at least one support element may be configured to form a chamber inthe compressible member to accommodate expansion of the at least oneinflatable bladder. The or each support element may be expandable toform the chamber. The or each support element may be disposed alongsidethe inflatable bladder. The or each support element may be configured toform the chamber alongside the at least one inflatable bladder. The oreach support element may form a pocket. The inflatable bladder couldcomprise more than one pocket. For example, the inflatable bladder maycomprise first and second pockets for receiving respective first andsecond support members. The first and second pockets may be disposed onopposing sides of the inflatable bladder.

The insert may comprise one or more elongated sections. The insert mayoptionally comprise a plurality of the elongated sections. The elongatedsections may extend substantially parallel to each other. The insert maycomprise at least a first inflatable bladder and a second inflatablebladder. The first and second inflatable bladders may be inflatabletogether or independently of each other. The first inflatable bladdermay be disposed at a proximal end of the insert. The second inflatablebladder may be disposed at a distal end of the insert. The insert maycomprise a first port in fluid communication with the first inflatablebladder; and a second port in fluid communication with the secondinflatable bladder.

According to a further aspect of the present invention there is provideda method of forming a compressible member having at least one insert atleast partially encapsulated therein, the method comprising: disposingthe at least one insert in a mould cavity, the or each insert comprisingat least one inflatable bladder; and introducing a foaming material intothe mould cavity to form the compressible member, the foaming materialat least partially encapsulating the at least one insert.

The foaming material may comprise a thermoplastic elastomer foamingmaterial. The foaming material may be a polymer, such polyurethane (PU).The method may comprise forming a chamber in the compressible member toaccommodate expansion of the at least one inflatable bladder. The atleast one insert may comprise at least one support element forcooperating with a support arm to support the insert within the mouldcavity. The at least one support element may be configured to form apocket. The method may comprise expanding the pocket to form thechamber. The at least one support arm may be introduced into the pocketto expand the pocket. The method may comprise removing the compressiblemember from the mould cavity by withdrawing the at least one support armfrom the pocket.

According to an aspect of the present invention there is provided a seatcushion comprising: a compressible member; and one or more inflatablebladders; wherein the compressible member comprises at least one chamberassociated with the or each inflatable bladder, the at least one chamberbeing pre-formed within the compressible member and configured toaccommodate expansion of at least part of the associated inflatablebladder. The one or more inflatable bladders may be at least partiallyencapsulated within the compressible member.

According to a further aspect of the present invention there is provideda seat cushion comprising: at least first and second inflatablebladders, the first and second inflatable bladders being inflatableindependently of each other; a control system for control of theinflation and deflation of the first and second inflatable bladders toinduce a rolling hip motion and/or a pitching hip motion. The rollinghip motion and/or the pitching hip motion may induce a rhythmic motionof the hips and/or spine of a seat occupant which is representative ofthe motion occurring when a person is walking. The first and secondinflatable bladders may be alternately inflated and deflated to inducethe rolling hip motion and/or the pitching hip motion. The firstinflatable bladder may be inflated as the second inflatable bladder isdeflated; and the first inflatable bladder may be deflated as the secondinflatable bladder is inflated. In use, the seat cushion may provide ananti-fatigue function. It is believed that this may enhance spinallubrication and/or increase blood flow compared to a static posture. Thecontrol system may be configured such that the rolling hip motion and/orthe pitching hip motion have a frequency which approximates the cadenceof a person walking, for example a cadence of 100 steps per minute. Theinflation and deflation of each inflatable bladder represents oneoperating cycle. The control system may be configured such that thefirst and second inflatable bladders each perform in the range of 20 to100 operating cycles per minute. The control system may be configuredsuch that the first and second inflatable bladders each perform in therange of 30 to 70 operating cycles per minute. The control system may beconfigured such that the first and second inflatable bladders eachperform 50 operating cycles per minute. The inflatable bladders may bedisposed on opposing sides of the seat cushion. The inflatable bladdersmay be disposed in front and rear positions respectively.

According to a further aspect of the present invention there is provideda method of controlling inflatable bladders disposed in a seat cushionto provide an anti-fatigue function, the method comprising: selectivelyinflating and deflating at least first and second inflatable bladdersdisposed in the seat cushion to induce a rolling hip motion and/or apitching hip motion. The method may comprise inflating and deflatingeach of the first and second inflatable bladders 20 to 100 times perminute. The method may comprise inflating and deflating each of thefirst and second inflatable bladders 30 to 70 times per minute. Themethod may comprise inflating and deflating each of the first and secondinflatable bladders 50 times per minute. The inflatable bladders may bedisposed on opposing sides of the seat cushion. The inflatable bladdersmay be disposed in front and rear positions respectively.

According to a further aspect of the present invention there is provideda vehicle comprising one or more vehicle seat assembly as describedherein.

According to a further aspect of the present invention there is provideda control system for controlling inflation of a seat cushion in a seatassembly, wherein the seat cushion comprises one or more inflatablebladders and a seat cushion cover; the control system comprising one ormore controllers, the control system being configured to: determine anoccupancy status of the seat assembly, the occupancy status indicatingone of a seat occupied state and a seat unoccupied state. In dependenceon the determined occupancy status indicating that the seat assembly isin a seat unoccupied state, the control system may generate a pressureincrease signal to increase an inflation pressure of the one or moreinflatable bladders to reduce sag in the seat cushion cover. In use, theone or more inflatable bladders may be inflated to reduce sag in theseat cushion cover. The volume of the or each inflatable bladderincreases as the inflation pressure increases. The resulting expansionof the seat cushion may increase the tension of the seat cushion cover.The reduced sag in the seat cushion cover may, for example,pre-condition the seat cushion. The seat cushion may be pre-conditionedto receive an occupant. The inflation of the one or more inflatablebladders may reduce or minimise sagging of the seat cover, therebyimproving the appearance of the seat assembly. A perceived quality ofthe seat cushion may be improved. The seat assembly may be installed ina vehicle. The seat cushion may be pre-conditioned for an individual,for example prior to or concurrent with the individual entering thevehicle.

The seat assembly may be provided in a vehicle. For example, the seatassembly may be provided in a first (front) row of a vehicle.Alternatively, the seat assembly may be provided in a second row or athird row of a vehicle.

The one or more controllers may be configured to receive an occupancystatus signal. For example, the one or more controllers may receive theoccupancy status signal from seat occupancy sensing means, such as oneor more seat occupancy sensor. The one or more seat occupancy sensor maybe configured to detect the presence or absence of a seat occupant. Theseat occupancy sensor(s) may comprise a load sensor for detecting a loadindicative of a person sitting in the seat assembly. Alternatively, orin addition, the seat occupancy sensor may comprise an imaging systemfor detecting the presence or absence of a person sitting in the seatassembly. The occupancy status signal may indicate one of the seatoccupied state and the seat unoccupied state.

The one or more controllers may collectively comprise at least oneelectronic processor having an electrical input for receiving a seatoccupancy status signal indicating the occupancy status of the seatassembly; and at least one memory device electrically coupled to the atleast one electronic processor and having instructions stored therein.The at least one electronic processor may be configured to access the atleast one memory device and execute the instructions thereon so as togenerate the pressure increase signal to increase an inflation pressureof the one or more inflatable bladders.

The one or more controllers may be configured to generate the pressureincrease signal. The pressure increase signal may be output to one ormore valves for controlling a supply of pressurised air to the one ormore inflatable bladders. Alternatively, or in addition, the pressureincrease signal may be output to a pump or compressor for supplyingpressurised air to the one or more inflatable bladders.

The control system may be configured to receive a seat occupancy signalindicating that the seat assembly is occupied or unoccupied. Theoccupancy status may be determined in dependence on the seat occupancysignal. The control system may be configured to receive an activationsignal. The pressure increase signal may be generated in dependence onreceipt of the activation signal.

The seat assembly may be installed in a vehicle having a vehicle door.The activation signal may be generated in dependence on one or more ofthe following: detection of an activation of an electronic deviceassociated with the vehicle; determination that the vehicle door isunlocked; determination that the vehicle door is opened; and/ordetermination that a handle of the vehicle door is actuated. Theelectronic device may, for example, comprise a key fob, or a cellulartelephone.

The control system may be configured to monitor the occupancy status toidentify a first change from the seat unoccupied state to the seatoccupied state. In dependence on identification of the first change inthe determined occupancy status, the control system may generate adecrease pressure signal to decrease the inflation pressure of the oneor more inflatable bladders. The decrease in the inflation pressure mayreduce the firmness of the seat cushion, for example to improve comfort.In use, the control system may reduce the inflation pressure when anoccupant sits in the seat assembly. The controlled reduction in theinflation pressure may provide a seat welcome feature on initial sit-invia the relaxing effect of the partial or complete deflation of thefirst and second inflatable bladders.

The seat assembly may be configurable in a deployed condition (forseating an occupant); and a stowed condition (for reducing the spaceoccupied by the seat assembly). The control system may be configured todetect whether the seating assembly is in a deployed condition or in astowed condition. The control system may be configured to inhibitincreases in the pressure of the one or more inflatable bladders if theseat assembly is in a stowed condition. The control system may beconfigured to detect a change in the condition of the seat assembly froma stowed condition to a deployed condition; and/or from a deployedcondition to a stowed condition. The control system may be configured toincrease the pressure of the one or more inflatable bladders upondetecting a change in the condition of the seat assembly from the stowedcondition to the deployed condition. The pressure of the one or moreinflatable bladders may be increased once the seat assembly is in thedeployed condition or as the seat assembly is re-configured to thedeployed condition. The control system may be configured to decrease thepressure of the one or more inflatable bladders upon detecting a changein the condition of the seat assembly from the deployed condition to thestowed condition. The pressure of the one or more inflatable bladdersmay be decreased once the seat assembly is in the stowed condition or asthe seat assembly is re-configured to the stowed condition.

According to a still further aspect of the present invention there isprovided a control system for controlling inflation of a seat cushion ina seat assembly, wherein the seat cushion comprises one or moreinflatable bladders and a seat cushion cover; the control systemcomprising one or more controllers, the control system being configuredto: determine an occupancy status of the seat assembly, the occupancystatus indicating one of a seat occupied state and a seat unoccupiedstate; and monitor the occupancy status to identify a first change fromthe seat unoccupied state to the seat occupied state. In dependence onidentification of the first change in the determined occupancy status,the control system may generate a decrease pressure signal to decreasethe inflation pressure of the one or more inflatable bladders. Thecontrol system may be configured to monitor the occupancy status toidentify a second change from the seat occupied state to the seatunoccupied state. In dependence on identification of the second changein the determined occupancy status, the control system may generate thepressure increase signal to increase the inflation pressure of the oneor more inflatable bladders. The control system may be configured toidentify or predict when the occupant is vacating the seat assembly. Independence on the identification or prediction, the control system maygenerate the pressure increase signal to increase the inflation pressureof the one or more inflatable bladders. Increasing the inflationpressure of the one or more inflatable bladders may help the occupant asthey vacate the seat assembly.

According to a still further aspect of the present invention there isprovided a control system for controlling inflation of a seat cushion ina seat assembly, wherein the seat cushion comprises one or moreinflatable bladders and a seat cushion cover; the control systemcomprising one or more controllers, the control system being configuredto: determine an occupancy status of the seat assembly, the occupancystatus indicating one of a seat occupied state and a seat unoccupiedstate; and identify or predict when the occupant is vacating the seatassembly. In dependence on the identification or prediction, the controlsystem may generate a pressure increase signal to increase the inflationpressure of the one or more inflatable bladders. The one or moreinflatable bladders may be provided in a seat cushion provided in theseat base. The seat cushion may, for example, comprise or consist of acentral seating region. The seat assembly may comprise one or more sidebolsters. The one or more side bolsters may be disposed in a lateralposition of the seat assembly. The one or more side bolsters may beassociated with the seat back and/or the seat base. One or moreinflatable bladders may be provided in the or each side bolster. Independence on the identification or prediction, the control system maygenerate a pressure decrease signal to decrease the inflation pressureof the one or more inflatable bladders disposed in the or each sidebolster. The control system may decrease the inflation pressure of theside bolster disposed proximal to a vehicle door to facilitate egressfrom the vehicle. The control system may optionally increase theinflation pressure of the side bolster disposed distal from the vehicledoor to facilitate egress from the vehicle. The control system maymonitor the occupancy status to identify a change from the seat occupiedstate to the seat unoccupied state. Identification of the change may beused by the control system to identify that the occupant is vacating theseat assembly. The control system may be configured to identify orpredict that an occupant is vacating (or preparing to vacate) the seatassembly by identifying an indicator. The indicator may, for example,comprise actuation of a door handle of the vehicle door. The controlsystem may, for example, receive a door opening signal. Other indicatorsmay include one or more of the following: engagement of a parking brake;selection of a parked gear; removal of a key; un-buckling or un-latchingof a seatbelt associated with the seat. The control system may beconfigured to identify or predict that the seat assembly will beoccupied. The pressure increase signal may be generated in dependence onthe identification. The seat cushion may be preconditioned for anindividual prior to them occupying the seat assembly. The detection ofan electronic device, such as a key fob or cellular telephone, may beused to identify or predict that the seat assembly will be occupied. Theelectronic device may be associated with the vehicle in which the seatassembly is installed. The seat cushion may comprise at least first andsecond inflatable bladders. The control system may be configured toincrease or decrease the inflation pressure of the first and secondinflatable bladders in a predetermined sequence. The pressure increasesignal may control inflation of the first and second inflatable bladdersin a predetermined sequence. For example, the first inflatable bladdermay be inflated and then the second inflatable bladder may be inflated.The control system may be configured to set a target inflation pressurefor the one or more inflatable bladders. The pressure increase signalmay increase the inflation pressure of the one or more inflatablebladders to a target inflation pressure. The control system may beconfigured to inflate the first and second inflatable bladders to thesame inflation pressure or to different inflation pressures. Thedifferent inflation pressures may, for example, reflect different sagproperties of the seat cushion cover. The control system may beconfigured to estimate usage of the seat assembly and to set the targetinflation pressure in dependence on the estimated usage. The controlsystem may estimate usage in dependence on one or more of the following:elapsed time, such as the age of the vehicle; mileage (total distancetravelled) of the vehicle; a cumulative time that the seat assembly isoccupied; and a total ingress/egress cycles for the seat assembly. Thepressure increase signal may control operation of at least one valveassociated with the or each inflatable bladder; and/or operation of apump or compressor for inflating the one or more inflatable bladders.The control system may be configured to detect the presence or absenceof an object on the seat assembly. The control system may be configuredto inhibit generation of the pressure increase signal when the object ispresent. The object, may, for example be a child seat. The child seatmay be fastened using a mechanical locking mechanism. The lockingmechanism may communicate with a vehicle system to indicate the presenceof the child seat. Alternatively, the object may be a load, such as acontainer, a bag or a package. The object may be detected using a loador weight sensor. The object may be detected using an optical or thermalsensor arranged to monitor the occupancy status of one or more seats.

According to a further aspect of the present invention there is provideda vehicle comprising a control system as described herein. The vehiclemay comprise at least one seat assembly having a seat cushion. The seatcushion may have a seat cushion cover and one or more inflatablebladders. The control system may be configured to generate a pressureincrease signal to control an inflation pressure of the one or moreinflatable bladders to reduce sag of the seat cushion cover.

According to a further aspect of the present invention there is provideda method of controlling inflation of a seat cushion in a seat assembly,the seat cushion comprising a seat cushion cover and one or moreinflatable bladders. The method may comprise determining an occupancystatus of the seat assembly, the occupancy status may indicate one of aseat occupied state and a seat unoccupied state. In dependence on thedetermined occupancy status indicating that the seat assembly is in aseat unoccupied state, the control system may increase an inflationpressure of the one or more inflatable bladders to reduce sag in theseat cushion cover. The seat assembly may be installed in a vehicle. Theseat assembly may be provided in a first (front) row of a vehicle.Alternatively, the seat assembly may be provided in a second row or athird row of a vehicle. The method may comprise increasing the inflationpressure of the one or more inflatable bladders in dependence on anactivation event. The seat assembly may be installed in a vehicle havinga vehicle door. The activation event may comprise one or more of thefollowing: activation of an electronic device associated with thevehicle; the vehicle door being unlocked; the vehicle door being opened;and/or actuation of a handle of the vehicle door. The method maycomprise identifying a first change in the occupancy status from theseat unoccupied state to the seat occupied state. In dependence onidentification of the first change, the method may comprise decreasingthe inflation pressure of the one or more inflatable bladders. Themethod may comprise identifying a second change in the occupancy statusfrom the seat occupied state to the seat unoccupied state. In dependenceon identification of the second change, the method may compriseincreasing the inflation pressure of the one or more inflatablebladders. The method may comprise identifying or predicting when theoccupant is vacating the seat assembly. In dependence on theidentification or prediction, the method may comprise increasing theinflation pressure of the one or more inflatable bladders. The seatcushion may comprise at least first and second inflatable bladders. Themethod may comprise increasing or decreasing the inflation pressure ofthe first and second inflatable bladders in a predetermined sequence.The method may comprise increasing the inflation pressure of the one ormore inflatable bladders to a target inflation pressure. The method maycomprise estimating usage of the seat assembly and setting the targetinflation pressure in dependence on the estimated usage. The method maycomprise detecting the presence or absence of an object. The method maycomprise inhibiting increases in the pressure of the one or moreinflatable bladders if the object is present. The object may be a childseat or other load. The seat assembly may be configurable in a deployedcondition (for seating an occupant); and a stowed condition (forreducing the space occupied by the seat assembly). The method maycomprise detecting whether the seating assembly is in a deployedcondition or in a stowed condition. The method may comprise inhibitingincreases in the pressure of the one or more inflatable bladders if theseat assembly is in a stowed condition. The method may comprisedetecting a change in the condition of the seat assembly from a stowedcondition to a deployed condition; and/or from a deployed condition to astowed condition. The method may comprise increasing the pressure of theone or more inflatable bladders upon detecting a change in the conditionof the seat assembly from the stowed condition to the deployedcondition. The pressure of the one or more inflatable bladders may beincreased once the seat assembly is in the deployed condition or as theseat assembly is re-configured to the deployed condition. The method maycomprise decreasing the pressure of the one or more inflatable bladdersupon detecting a change in the condition of the seat assembly from thedeployed condition to the stowed condition. The pressure of the one ormore inflatable bladders may be decreased once the seat assembly is inthe stowed condition or as the seat assembly is re-configured to thestowed condition.

According to a still further aspect of the present invention there isprovided a computer software that, when executed, is arranged to performa method as described herein.

According to a still further aspect of the present invention there isprovided a non-transitory, computer-readable storage medium storinginstructions thereon that, when executed by one or more electronicprocessors, causes the one or more electronic processors to carry outthe method described herein.

Within the scope of this application it is expressly intended that thevarious aspects, embodiments, examples and alternatives set out in thepreceding paragraphs, in the claims and/or in the following descriptionand drawings, and in particular the individual features thereof, may betaken independently or in any combination. That is, all embodimentsand/or features of any embodiment can be combined in any way and/orcombination, unless such features are incompatible. The applicantreserves the right to change any originally filed claim or file any newclaim accordingly, including the right to amend any originally filedclaim to depend from and/or incorporate any feature of any other claimalthough not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by wayof example only, with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic representation of a vehicle comprising vehicleseat assemblies having a seat cushion in accordance with an embodimentof the present invention;

FIG. 2 shows a side elevation of one of the vehicle seat assembly shownin FIG. 1 ;

FIG. 3 shows a schematic plan view representation of a seat cushionaccording to an embodiment of the present invention;

FIG. 4 shows a sectional view of the seat cushion shown in FIG. 3 ;

FIGS. 5A, 5B, 5C, 5D and 5E show stages in the moulding of the seatcushion in accordance with an embodiment of the present invention;

FIG. 6 shows a block diagram representing the process of manufacturing aseat cushion in accordance with an embodiment of the present invention

FIG. 7 shows a schematic plan view representation of a variant of theseat cushion shown in FIG. 3 ;

FIG. 8 shows a perspective view of the seat cushion shown in FIG. 7 ;

FIG. 9 shows a perspective view of a compressible member of the seatcushion shown in FIGS. 7 and 8 ;

FIG. 10A shows a sectional view of the seat cushion shown in FIG. 3illustrating sag in an upper region of the seat cover;

FIG. 10B shows a sectional view of the seat cushion shown in FIG. 3illustrating reduced sag in the upper region of the seat cover;

FIG. 11 shows a block diagram representing the operation of the systemcontroller in accordance with an embodiment of the present invention.

FIG. 12 shows a schematic plan view representation of a seat cushionaccording to a further embodiment of the present invention;

FIG. 13 shows a schematic representation of a controller for controllinginflation and deflation of the one or more inflatable bladders providedin the seat cushion.

DETAILED DESCRIPTION

A seat cushion 1 in accordance with an embodiment of the presentinvention is described herein with reference to the accompanyingFigures. As described herein, the stiffness of the seat cushion 1 can beadapted to suit specific requirements.

The seat cushion 1 in the present embodiment is disposed in a seatassembly 2 of a vehicle V. As shown in FIG. 1 , the vehicle V is anautomobile in the present embodiment. The seat cushion 1 could be usedin other types of vehicle V, such as a utility vehicle, a tractor unit,a train, a ship or an aircraft. The seat cushion 1 and the seat assembly2 are described herein with reference to a reference frame comprising alongitudinal axis X, a transverse axis Y and a vertical axis Z. Thevehicle V has a cabin C in which a plurality of the seat assemblies 2are mounted. The cabin C has at least first and second doors D-n foringress/egress. For the sake of brevity, only one of the seat assemblies2 is described herein.

As shown in FIG. 2 , the vehicle seat assembly 2 comprises a seat base 3and a seat back 4. The seat cushion 1 in the present embodiment formspart of the seat base 3. Alternatively, or in addition, the seat cushion1 could form part of the seat back 4. The seat cushion 1 is supported inthe seat base 3 by a seat pan 5 mounted to a seat chassis (not shown).The seat chassis may be in the form of a seat frame or seat structure.The seat pan 5 comprises a plate member for supporting the seat cushion1. The seat chassis is mounted to the floor of the vehicle V. The seatchassis may enable the longitudinal and/or vertical position of the seatpan 5 to be adjusted relative to a floor of the vehicle V. As shown inFIG. 3 , the seat cushion 1 comprises a central seating region 6 and athigh support 7 for supporting the thighs of a seat occupant. Theposition of the thigh support 7 relative to the central seating region 6may be adjustable, for example to adjust the thigh support for the seatoccupant. The vertical and/or longitudinal position of the thigh support7 may be adjustable relative to the central seating region 6. The seatback 4 comprises a frame (not shown) which supports a back-supportcushion 8 and opposing lateral lumbar supports (not shown). The seatback 4 also comprises a head rest 10. The seat back 4 may be pivotallymounted to the seat chassis to enable a recline angle of the seat back 4to be adjusted relative to the seat base 3. A first seat cover 11 isprovided over the seat base 3 to protect the seat cushion 1. A secondseat cover 12 is provided over the seat back 4. At least in certainembodiments, the vehicle seat assembly 2 may be selectively configurablein a deployed condition (for seating an occupant); and a stowedcondition (for reducing the space occupied by the seat assembly). Thevehicle seat assembly 2 is illustrated in the deployed condition in FIG.2 . In the stowed condition, the seat back 4 is typically pivotedforwards such that the back-support cushion 8 faces the seat cushion 1.

The composition of the seat cushion 1 will now be described. The seatcushion 1 comprises a compressible member 15 and at least one insert 16.The compressible member 15 is a foam member. The or each insert 16 is atleast partially encapsulated within the compressible member 15. Asdescribed herein, the or each insert 16 is co-moulded with thecompressible member 15. The insert 16 is integral with the compressiblemember 15. The compressible member 15 is moulded from a foamingmaterial, such as a thermoplastic elastomer foaming material, which isintroduced into a mould cavity 51. The insert 16 is pre-formed andintroduced into the mould cavity 51 prior to introduction of the foamingmaterial. Thus, the insert 16 is at least partially encapsulated by thefoam in the mould cavity 51. The forming of the seat cushion 1 isdescribed in more detail herein with reference to FIGS. 5A, 5B and 5C.The compressible member 15 may comprise a foam having an open cell or aclosed cell structure. The seat cushion 1 in the present embodimentcomprises a single insert 16 which is encapsulated within thecompressible member 15. The insert 16 comprises at least one inflatablebladder 17-n. The or each inflatable bladder 17-n comprises at least oneport 18-n for connection to a pressurised gas supply, typically apressurised air supply. The or each inflatable bladder 17-n has amulti-cell composition to promote inflation in a single axis. In thepresent embodiment, each inflatable bladder 17-n comprises first andsecond cells disposed on top of each other to promote expansion in avertical axis.

The insert 16 comprises first and second inflatable bladders 17-1, 17-2which are inflatable independently of each other. The first inflatablebladder 17-1 is associated with a rear portion of the seating region 6;and the second inflatable bladder 17-2 is associated with a frontportion of the seating region 6. In a variant, the second inflatablebladder 17-2 (and/or a separate inflatable bladder) may be associatedwith the thigh support 7. The first and second inflatable bladders 17-1,17-2 have respective first and second ports 18-1, 18-2. The first andsecond ports 18-1, 18-2 are positioned at a first end of the seatcushion 1 for location proximal to the seat back 4 in the seat assembly2. The first inflatable bladder 17-1 comprises a plurality of elongatedfirst tubular members 19-1, each of the first tubular members 19-1 beingin fluid communication with the first port 18-1. In the presentembodiment, the first inflatable bladder 17-1 comprises six (6) of thefirst tubular members 19-1, but less than six (6) and more than six (6)first tubular members 19-1 are also contemplated. The second inflatablebladder 17-2 comprises a plurality of elongated second tubular members19-2, the second tubular members 19-2 each being in fluid communicationwith the second port 18-2. In the present embodiment, the secondinflatable bladder 17-2 comprises six (6) of the second tubular members19-2, but less than six (6) and more than six (6) second tubular members19-2 are also contemplated. In the present embodiment, the first andsecond tubular members 19-1, 19-2 are arranged in pairs extending alonga longitudinal axis.

As shown in FIG. 3 , a first supply line 20-1 connects the first tubularmembers 19-1 to each other and to the first port 18-1. As shown in FIG.3 , at least one second supply line 20-2 (shown in dashed lines)connects the second tubular members 19-2 to each other and to the secondport 18-n. The second inflatable bladder 17-2 comprises a plurality ofsecond fluid supply lines 20-2. The second fluid supply lines 20-2extend along the length of a corresponding one of the first tubularmembers 19-1 and open into the second tubular members 19-2. In avariant, the second inflatable bladder 17-2 may comprise a transverseline extending directly between the second tubular members 19-2. Thefirst and second inflatable bladders 17-1, 17-2 are each formed bybonding first and second gas-impermeable sheet members to each other toform sealed (fluid-tight) join lines which define the first and secondtubular members 19-1, 19-2. The first and second fluid supply lines20-1, 20-2 may be formed integrally with the first and second inflatablebladders 17-1, 17-2, for example by forming sealed join lines. Othertechniques may be employed to form the first and second tubular members19-1, 19-2. The first and second ports 18-1, 18-2 are bonded to thesheet members, for example using an adhesive or thermal bonding agent.

The seat cushion 1 comprises a plurality of chambers 21 associated withthe or each inflatable bladder 17-1, 17-2. In the present embodiment,the chambers 21 are formed below the or each inflatable bladder 17-1,17-2. The chambers 21 are hollow voids formed within the compressiblemember 15. In the present embodiment, one of the chambers 21 is formedadjacent to each of the tubular members 19-1, 19-2. The or each chamber21 is pre-formed within the compressible member 15 and functions as anexpansion chamber into which the associated inflatable bladder 17-1,17-2 can expand. By pre-forming the at least one chamber 21, theinflatable bladder 17-1, 17-2 can expand within the compressible member15. At least in certain embodiments, this expansion can occur withreduced or minimal localised compression of the compressible member 15.The insert 16 comprises one or more support elements 22. The or eachsupport element 22 is configured to form a lining of an associated oneof the chambers 21 formed in the compressible member 15. In the presentembodiment, the insert 16 comprises a plurality of support elements 22each associated with a respective one of the first and second tubularmembers 19-1, 19-2. The support elements 22 each comprise a sleeve whichforms a pocket 24 which is open at a proximal first end and closed at adistal second end. In a variant, the pocket 24 may be open at both thefirst and second ends. The support element 22 may be formed integrallywith the insert 16, for example from one of the sheet members used toform the first and second inflatable bladders 17-1, 17-2.

The seat cushion 1 is injection moulded in a mould 50. The compressiblemember 15 is moulded from a foaming material and, as described herein,the insert 16 is at least partially encapsulated therein. Thefabrication process will now be described with reference to FIGS. 5A,5B, 5C, 5D and 5E. As shown in FIG. 5A, the mould 50 is opened and theinsert 16 located in a mould cavity 51. A support assembly 52 isprovided to support the insert 16 in the desired location within themould cavity 51. The support assembly 52 is movable between a firstposition for performing the moulding process, and at least one secondposition for removal/insertion of the moulded seat cushion 1. Thesupport assembly 52 is pivotally mounted to enable movement between thefirst and second positions. In use, the support assembly 52 pivotsthrough an angle of between 30° and 45° as it moves between the firstand second positions. Alternatively, or in addition, the supportassembly 2 may translate between the first and second positions. Thesupport assembly 52 comprises a plurality of support arms 53 arranged tolocate within respective pockets 24 formed by the support elements 22.The support arms 53 are inserted through the open first end 25 of eachpocket 24. The support arms 53 are profiled to expand the pockets 24formed in the insert 16. An end view of the support arms 53 disposed inthe pockets 24 is shown in FIG. 5A. A releasable retaining device, suchas a vacuum pump may optionally be used to retain the insert 16 on thesupport assembly 52. The support arms 53 are configured to form thechambers 21 within the compressible member 15. In particular, thesupport arms 53 are sized to expand the pockets 24 when the insert 16 isdisposed on the support assembly 52.

The support assembly 52 is secured in the first position within themould cavity 51 and the mould closed, as shown in FIG. 5B. The foamingmaterial is introduced into the mould cavity 51 to form the compressiblemember 15. The foaming material at least substantially fills the mouldcavity 51. The foaming material fills the region around the first andsecond tubular members 19-1, 19-2, thereby at least partiallyencapsulating the insert 16. The foaming material cures and the mouldcavity 51 is opened. The support assembly 52 is displaced from the firstposition to the second position. As shown in FIG. 5C, the seat cushion 1is removed from the mould cavity 51 by sliding the seat cushion 1 offthe support assembly 52. The support arms 53 are removed from thepockets 24, thereby opening the chamber(s) 21 within the compressiblemember 15. The support element 22 prevents or reduces contact betweenthe foaming material and the support arms 53 thereby facilitatingremoval of the seat cushion 1 from the support assembly 52. The insert16 is co-moulded into the compressible member 15 of the seat cushion 1.The pockets 24 are disposed on an upper side of the insert 16 such thatthe chambers 21 are formed above the insert 16. In a variant, thepockets 24 may be disposed on an underside of the insert 16 such thatthe chambers 21 are formed below the insert 16. The insert 16 mayoptionally comprise one or more interlocking features to secure theinsert 16 in the compressible member 15.

In accordance with some embodiments of the present invention, and asillustrated in FIGS. 5D and 5E, during the moulding process first andsecond ports 18-1, 18-2 may be held within a locating element 18-3. Thelocating element 18-3 is configured to be located within the mould 50and during the moulding process to accurately locate and hold in placethe first and second ports 18-1, 18-2 and the ends of the supply lines20-1, 20-2 connected thereto. During the moulding process, the locatingelement 18-3 is only partially encapsulated within the compressiblemember such that once the seat cushion 1 has been removed from the mouldcavity 51 the first and second ports 18-1, 18-2 are accessible forsubsequent connection to a pressurised gas supply.

Advantageously, the locating element 18-3 enables the ends of the firstand second ports 18-1, 18-2 and the ends of the supply lines 20-1, 20-2connected thereto to be accurately located and held in place during themoulding process without squashing the ports 18-1, 18-2 and the supplylines 20-1, 20-2, and helps to prevent the foaming material entering theports 18-1, 18-2 and the supply lines 20-1, 20-2 during the mouldingprocess.

In some embodiments, the locating element 18-3 may comprise apolyurethane block. In addition, the foaming material used for thecompressible member 15 may comprise expanded polyurethane. In thismanner, the locating element and foaming material bond together duringthe moulding process to facilitate retention of the locating element18-3 within the compressible member 15.

Once the seat cushion 1 has been moulded, the first and secondinflatable bladders 17-1, 17-2 are inflated by introducing pressurisedgas through the first and second ports 18-1, 18-2. In the presentembodiment, the first and second inflatable bladders 17-1, 17-2 arepneumatic bladders for inflation with pressurised air. The first andsecond tubular members 19-1, 19-2 inflate at least partially to fill thechambers 21 formed in the compressible member 15. The properties of theseat cushion 1 can be controlled in dependence on the inflation pressureof the first and second inflatable bladders 17-1, 17-2. A targetinflation pressure may be specified for the first inflatable bladder17-1 and/or the second inflatable bladder 17-2. The target inflationpressure may be specified by a user, for example using an input device;or by a vehicle system, for example in dependence on a current drivingmode of the vehicle V. In the present embodiment, the inflation pressureis controllable to enable dynamic adjustment of the properties of theseat cushion 1, for example controllably to increase or decreasestiffness. The first and second ports 18-1, 18-2 are configured to beconnected to a pressurised air supply 28 for supplying pressurised airto inflate the first and second inflatable bladders 17-1, 17-2. Thepressurised air supply 28 comprises an air compressor 29 and at leastone reservoir 30. The pressurised air supply 28 comprises first andsecond connectors 31-1, 31-2 for connection to the first and secondports 18-1, 18-2. First and second valves 32-1, 32-2 are provided forcontrolling the supply of pressurised air to the first and secondinflatable bladders 17-1, 17-2. The first and second valves 32-1, 32-2are associated with the first and second ports 18-1, 18-2 respectively.The first and second valves 32-1, 32-2 are two-way valves which can beselectively opened and closed to control inflation and deflation of thefirst and second inflatable bladders 17-1, 17-2. The first and secondvalves 32-1, 32-2 are operable independently of each other to enablecontrol of the inflation pressure of each of the first and secondinflatable bladders 17-1, 17-2. The first and second inflatable bladders17-1, 17-2 may have the same or different inflation pressures. The seatcushion 1 could optionally include one or more pressure sensors (notshown) for measuring the pressure in the first and second inflatablebladders 17-1, 17-2. In a variant, the inflation pressure of the firstand second inflatable bladders 17-1, 17-2 may be fixed, for example bysealing the first and second ports 18-1, 18-2 when the first and secondinflatable bladders 17-1, 17-2 have been inflated to the desiredinflation pressure.

The process of integrally forming the compressible member 15 and theinsert(s) 16 is represented by a block diagram 100 shown in FIG. 6 . Theinsert(s) 16 is disposed in the mould cavity 51 (BLOCK 105). Asdescribed herein, the or each insert 16 is disposed on a support arm 53.The support arm 53 is introduced into a pocket 24 formed in each insert16. The or each pocket 24 is thereby expanded by the support arm 53. Insome embodiments, the locating element 18-3 is located within the mould50 (BLOCK 110) to locate and hold in place the first and second ports18-1, 18-2 and the ends of the supply lines 20-1, 20-2 connectedthereto. A foaming material is introduced into the mould cavity 51 toform the compressible member 15 (BLOCK 115). The foaming materialintroduced into the mould cavity 51 at least partially encapsulates theat least one insert 16. The foaming material is allowed to cure (BLOCK120). The compressible member 15 is removed from the mould cavity 51(BLOCK 125).

According to some embodiments, the vehicle V comprises means fordetermining an occupancy status of the seat assembly 2. The occupancystatus may indicate that the seat assembly 2 is either in a seatoccupied state (i.e. the seat assembly 2 is occupied) or a seatunoccupied state (i.e. the seat assembly 2 is unoccupied). The occupancydetermining means comprises one or more seat occupancy sensor 25 fordetecting the presence or absence of a seat occupant. In the presentembodiment, the seat occupancy sensor 25 comprises a load sensor fordetecting a load (or weight) indicative of a person sitting in the seatassembly 2. The seat occupancy sensor 25 is disposed in the centralseating region 6 of the seat assembly 2, for example below the seatcushion 15. It will be understood that a seat occupancy sensor 25 may beprovided for one or more of the vehicle seats 2 disposed in the vehicleV. The occupancy status may be determined in respect of one or more ofthe vehicle seats 2 in the vehicle V. The seat occupancy sensor 25 isconfigured to output a seat occupancy status signal SOCC indicating theoccupancy status of the seat assembly 2. Other types of sensor, such asa pressure sensor, may be used as the seat occupancy sensor 25. In avariant, the seat occupancy sensor 25 may comprise or consist of animaging system comprising one or more camera, for example comprising anoptical camera or a thermal imaging camera.

In a variant, the seat occupancy sensor 25 may be implemented by anin-cabin imaging system (not shown). The cabin imaging system may beconfigured to determine the occupancy status of one or more of thevehicle seats 2. The cabin imaging system may comprise at least oneimaging sensor, such as an optical or thermal camera, for determiningwhen one or more person is within the cabin of the vehicle V. The atleast one imaging sensor can be arranged to capture an image of aninterior of the cabin. The imaging sensor may be disposed in an upperregion of the cabin of the vehicle V, for example mounted in aheadlining, or disposed in a housing of a rear-view mirror; or may bedisposed in an instrument panel or a dashboard of the vehicle V. Thecabin imaging system may comprise an image processor for determining theoccupancy status of the seat assembly 2. The image processor may processimage data captured by the at least one imaging sensor in order toidentify the presence or absence of a person in a region associated withone or more of the vehicle seats 2. The image processor may therebydetermine an occupancy status of one or more of the vehicle seats 2.

In the present embodiment, the vehicle V comprises a remote accesssystem 26 for implementing remote control of one or more vehiclesystems. The remote access system 26 may, for example, comprise aPassive Entry Passive Start (PEPS) system or an enhanced Passive EntryPassive Start (ePEPS) system. The remote access system 26 may controlone or more door lock or security latches for securing the vehicle doorsD-n. The latch(es) may, for example, be unlocked when the remote accesssystem 26 is activated. The remote access system 26 in the presentembodiment comprises a base unit 27A provided in the vehicle V and aremote control unit 27B, for example comprising a key fob or a cellulartelephone. A user may activate the remote control unit 27B to unlock oneor more of the vehicle doors D-n. Alternatively, or in addition, theactivation may be performed automatically when the base unit 27A detectsthe remote control unit 27B. The base unit 27A and the remote controlunit 27B may perform an electronic handshake to determine that theremote control unit 27B is associated with the vehicle V. If theelectronic handshake is successful, the base unit 27A is configured tooutput an access signal SACC to unlock one or more of the vehicle doorsD-n. In a variant, the remote access system 26 could be configured torelease a door opening mechanism at least partially to open the vehicledoor D-n.

A control system 33 is provided for controlling operation of the firstand second valves 32-1, 32-2. The control system 33 is provided in thevehicle V, for example as a module with a vehicle system controller, andconnected to the seat assembly 2. In a variant, the control system 33could be incorporated into the seat assembly 2, for example in a seatcontrol panel. The control system 30 is configured to generate first andsecond control signals SOUT1, SOUT2 for controlling operation of thefirst and second valves 32-1, 32-2. When activated, the control system33 is configured to open the first and second valves 32-1, 32-2 toinflate the first and second inflatable bladders 17-1, 17-2. The controlsystem 33 is configured to close the first and second valves 32-1, 32-2when the first and second inflatable bladders 17-1, 17-2 are atrespective target inflation pressures. The control system 33 maydetermine the inflation pressure of the first and second inflatablebladders 17-1, 17-2 in dependence on a signal from one or more pressuresensors. Alternatively, the control system 33 may control the inflationpressure of the first and second inflatable bladders 17-1, 17-2 byopening the first and second valves 32-1, 32-2 for a predeterminedperiod of time. The control system 33 in the present embodiment isactivated when the vehicle V is unlocked or a door of the vehicle V isopened. The seat cushion 1 may be pre-conditioned to receive an occupantupon entering the vehicle V. The inflation of the first and secondinflatable bladders 17-1, 17-2 may reduce or minimise sagging of thefirst seat cover 11, thereby improving the appearance of the seatassembly 2. A perceived quality of the seat cushion 1 may be improved.The control system 33 may optionally be configured to reduce theinflation pressure when an occupant sits in the seat assembly 2. Thecontrolled reduction in the inflation pressure may provide a seatwelcome feature on initial sit-in via the relaxing effect of the partialor complete deflation of the first and second inflatable bladders.

The seat assembly 2 is installed in the vehicle V and the pressurisedair supply 28 is connected to the first and second inflatable bladders17-1, 17-2 via the first and second ports 18-1, 18-2. The control system33 is activated and outputs the first and second control signals SOUT1,SOUT2 to open the first and second valves 32-1, 32-2. The pressurisedair supply 28 supplies pressurised air and inflates the first and secondinflatable bladders 17-1, 17-2. The first and second valves 32-1, 32-2may be operated in parallel, such that the first and second inflatablebladders 17-1, 17-2 are inflated concurrently; or may be operatedsequentially, such that the first and second inflatable bladders 17-1,17-2 are inflated one after the other. The control system 33 outputs thefirst and second control signals SOUT1, SOUT2 to close the first andsecond valves 32-1, 32-2 when the first and second inflatable bladders17-1, 17-2 have been inflated to the desired inflation pressure. A usermay optionally control the inflation pressure of the first and secondinflatable bladders 17-1, 17-2, for example to increase or decrease theinflation pressure(s) of each of the first and second inflatablebladders 17-1, 17-2.

The second inflatable bladder 17-2 shown in FIG. 3 comprises a pluralityof second tubular members 19-2 extending in a longitudinal direction. Ina variant, the second inflatable bladder 17-2 may comprise one or moretubular members 19-2 which extend in a transverse direction. Thisarrangement is illustrated in FIGS. 7 and 8 . A perspective view of thecompressible insert 15 with the insert 16 omitted is shown in FIG. 9 .The control system 33 can be configured to vary the inflation pressureof the first and second inflatable bladders 17-1, 17-2 to provide acontrol function to provide an anti-fatigue (massage) function for aseat occupant. In particular, the inflation pressure of each of thefirst and second inflatable bladders 17-1, 17-2 can be increased anddecreased sequentially. By alternating the inflation and deflation ofthe first and second inflatable bladders 17-1, 17-2 out of phase witheach other, the seat cushion 1 induces a pitching hip motion for anoccupant of the seat assembly 2. The seat cushion 1 can be modified alsoto provide a rolling hip motion for the occupant. The anti-fatiguefunction provides an oscillation cycle which may provide longer-termcomfort and may mitigate the effects of back discomfort, via oscillationof the spine and surrounding muscular tissue. At least in certainembodiments, the anti-fatigue function may induce a rhythmic motion ofthe hips and/or spine of the occupant which is representative of themotion occurring when a person is walking. The oscillation cycle could,for example, have an operating frequency of 20 to 100 cycles per minute,for example 50 cycles per minute. It is believed that this may enhancespinal lubrication and/or increase blood flow compared to a staticposture.

A further operation of the control system 33 in relation to the seatassembly 2 according to some embodiments of the present invention willnow be described in more detail. It will be understood that the samecontrol strategy may be applied for more than one of the vehicle seats2.

The seat assembly 2 may be prone to sag over time due to a reduction inthe tautness of the first seat cover 11. A schematic representation ofsag in the first seat cover 11 is shown in FIG. 10A. Sag may be causedby stretching or deformation of the first seat cover 11, for example dueto repeated or prolonged use. Alternatively, or in addition, sag may becaused by deformation of the compressible member 15, for example due tolocalised or repeat loading. The first seat cover 11 is subject toincreased wear on the upper surface of the seat cushion 1 in the centralseating region 6. As illustrated in FIG. 10A, sag of the first seatcover 11 is most prevalent in this upper seating region. Whilst notaffecting the functionality of the seat assembly 2, the sag in the firstseat cover 11 may prove unsightly, particularly when the seat assembly 2is unoccupied. The control system 33 is configured to control inflationof at least one of the first and second inflatable bladders 17-1, 17-2to reduce or prevent sag of the first seat cover 11. In the presentembodiment, the control system 33 is configured to increase theinflation pressure of at least one of the first and second inflatablebladders 17-1, 17-2 to tension the first seat cover 11, thereby reducingsag. At least in certain embodiments, the appearance of the vehicle seat1 may be improved. A schematic representation of the reduced sag in thefirst seat cover 11 due to the increased inflation pressure of the firstinflatable bladders 17-1 is shown in FIG. 10B.

The sag of the first seat cover 11 is most apparent when the seatassembly 2 is unoccupied. To address this, the control system 33 isconfigured to increase the inflation pressure of at least one of thefirst and second inflatable bladders 17-1, 17-2 in dependence on adetermination that the seat assembly 2 is unoccupied. As outlined above,the seat occupancy sensor 25 outputs the seat occupancy status signalSOCC indicating the occupancy status of the seat assembly 2 (i.e. thatthe seat assembly 2 is occupied or unoccupied). The control system 33reads the seat occupancy status signal SOCC to determine when the seatassembly 2 is unoccupied.

The determination that the seat assembly 2 is unoccupied provides anentry condition for controlling inflation of the first and secondinflatable bladders 17-1, 17-2 to reduce sag of the first seat cover 11.The control system 33 is configured to control inflation of the firstand second inflatable bladders 17-1, 17-2 in dependence on thedetermination that the seat assembly 2 is unoccupied. The control system33 identifies one or more trigger events which, in combination with thedetermination that the seat assembly 2 is unoccupied, prompt the controlsystem 33 to increase the inflation pressure of at least one of thefirst and second inflatable bladders 17-1, 17-2. In the presentembodiment, the activation of the remote control unit 27B is the triggerevent for initiating an increase in the inflation pressure of the firstand second inflatable bladders 17-1, 17-2 to reduce sag. The controlsystem 33 receives the access signal SACC and checks the seat occupancystatus signal SOCC to determine if the seat assembly 2 is occupied orunoccupied. If the control system 33 determines that the seat assembly 2is unoccupied, the pressure increase signal SINC is generated to inflatethe first inflatable bladder 17-1 and/or the second inflatable bladder17-2. As shown in FIG. 10B the inflation of one or both of the first andsecond inflatable bladders 17-1, 17-2 reduces the sag of the first seatcover 11. It will be understood that other trigger events may be used toinitiate inflation of at least one of the first and second inflatablebladders 17-1, 17-2. Other trigger events include one or more of thefollowing: determination that the vehicle door D is unlocked;determination that the vehicle door D is opened; and/or determinationthat a handle associated with the vehicle door D is actuated.

The control system 33 is activated and generates the pressure increasesignal SINC. The pressure increase signal SINC comprises at least one ofthe first and second control signals SOUT1, SOUT2 for controllingoperation of the first and second valves 32-1, 32-2. The first andsecond valves 32-1, 32-2 are opened in response to the first and secondcontrol signals SOUT1, SOUT2. The air supply 28 supplies pressurised airto the first and second inflatable bladders 17-1, 17-2, therebyincreasing the inflation pressure of the first and second inflatablebladders 17-1, 17-2. The first and second valves 32-1, 32-2 may beoperated in parallel, such that the first and second inflatable bladders17-1, 17-2 are inflated concurrently; or may be operated sequentially,such that the first and second inflatable bladders 17-1, 17-2 areinflated one after the other. For example, the first inflatable bladder17-1 may be inflated before the second inflatable bladder 17-2; or thefirst inflatable bladder 17-1 may be inflated after the secondinflatable bladder 17-2. Alternatively, the pressure increase signalSINC may selectively open only one of the first and second valves 32-1,32-2. It is envisaged that the problem of sag of the first seat cover 11will be more prevalent in the central seating region 6 of the seatassembly 6. To counter sag in this region, the pressure increase signalSINC may consist of the first control signal SOUT1 to open the firstvalve 17-1 to inflate the first inflatable bladder 17-1.

The control system 33 outputs the first control signal SOUT1 to closethe first valve 32-1 when the inflation pressure of the first inflatablebladder 17-2 has increased to a first target inflation pressure. Thecontrol system 33 outputs the second control signal SOUT2 to close thesecond valve 32-2 when the inflation pressure of the second inflatablebladder 17-2 has increased to a second target inflation pressure. Thefirst and second target inflation pressures may be the same as eachother or different from each other. The degree to which sag occurstypically depends on the usage of the seat assembly 2. Stretching of thefirst seat cover 11 may increase as a result of repeated or extended useof the seat assembly 2 resulting in increased sag. The control system 33is configured to estimate usage of the seat assembly 2 and to set thefirst target inflation pressure and/or the second target inflationpressure in dependence on the estimated usage. In particular, thecontrol system 33 is configured to increase the first target inflationpressure and/or the second target inflation pressure in proportion tothe estimated usage. The usage may be estimated in dependence on one ormore of the following factors: vehicle age; vehicle mileage; acumulative time that the seat assembly 2 is occupied; the total numberof times that the seat assembly 2 has been used, for example a number ofingress/egress cycles. The usage may be estimated for each seat assembly2 in the vehicle 2; or may be estimated collectively for two or more ofthe seat assemblies 2.

The control system 33 pre-conditions the seat assembly 2 for the user.The increase in the inflation pressure of the first and secondinflatable bladders 17-1, 17-2 increases the volume of the seat cushion1 and gently stretches the first seat cover 11. The sag in the firstseat cover 11 is thereby reduced and the appearance of the seat assembly2 can be improved. The increase in the inflation pressure of the firstand second inflatable bladders 17-1, 17-2 may also increase the firmnessof the seat cushion 1. To improve comfort, the control system 33 isconfigured to reduce the inflation pressure of the first and secondinflatable bladders 17-1, 17-2 when an individual is seated on the seatassembly 2. The control system 33 monitors the seat occupancy statussignal SOCC to detect a change in the occupancy status. In particular,the control system 33 identifies a change from the seat unoccupied stateto a seat occupied state which indicates that an individual is seated inthe seat assembly 2. In dependence on this change in the seat occupancystatus, the control system 33 generates a pressure decrease signal SDECto reduce the inflation pressure. The pressure decrease signal SDECcomprises at least one first control signal SOUT1 and/or a secondcontrol signal SOUT2 to open one or both of the first and second valves32-1, 32-2 to release air. The reduction in the inflation pressure ofthe first and second inflatable bladders 17-1, 17-2 improves the comfortof the seat assembly 2, for example helping to ease the individual intothe seat assembly 2.

The control system 33 may be configured controllably to decrease theinflation pressure of the first and second inflatable bladders 17-1,17-2 to achieve a target inflation pressure. The control system 33 mayoutput the first control signal SOUT1 to close the first valve 32-1 whenthe inflation pressure of the first inflatable bladder 17-2 hasdecreased to a first target inflation pressure. The control system 33may output the second control signal SOUT2 to close the second valve32-2 when the inflation pressure of the second inflatable bladder 17-2has decreased to a second target inflation pressure. The first andsecond target inflation pressures may be the same as each other or maybe different from each other.

The control system 33 may be configured to identify or predict when theoccupant is vacating the seat assembly 2 or is preparing to vacate theseat assembly 2. The seat occupancy sensor 25 may detect an occupantmovement or a change in the measured load, which is indicative of theoccupant vacating the seat assembly 2. To facilitate egress from thevehicle V, the control system 33 may generate a pressure increase signalSINC in dependence on the determination that the occupant is vacatingthe seat assembly 2 or is preparing to vacate the seat assembly 2. Byincreasing the inflation pressure of the one or both of the first andsecond inflatable bladders 17-1, 17-2, the seat cushion 1 may help tolift or raise the occupant as they leave the seat assembly 2.

This operation of the control system 33 will now be described withreference to a first block diagram 100 shown in FIG. 11 . The operationof the control system 33 is initiated (BLOCK 205). The control system 33monitors the seat occupancy status signal SOCC generated by the seatoccupancy sensor 25 (BLOCK 210). The control system 33 determines if theseat assembly 2 is occupied or unoccupied (BLOCK 215). If the seatassembly 2 is occupied (OCC), the control system 33 continues to monitorthe seat occupancy. If the seat assembly 2 is unoccupied (UNOCC), thecontrol system 33 monitors one or more trigger event. One such triggerevent in the present embodiment is activation of the remote accesssystem 26 on the vehicle V. The base unit 27A provided on the vehicle Voutputs the access signal SACC (BLOCK 220). In dependence on receipt ofthe access signal SACC, the control system 33 generates a pressureincrease signal SINC (BLOCK 225). The pressure increase signal SINC isoutput to the first and second valves 32-1, 32-2 associated with thefirst and second inflatable bladders 17-1, 17-2 respectively (BLOCK230). The pressure increase signal SINC opens the first and secondvalves 32-1, 32-2 and pressurized air (i.e. air at greater thanatmospheric pressure) is introduced into the first and second inflatablebladders 17-1, 17-2 (BLOCK 235). The control system 33 may optionallymonitor (or estimate) the inflation pressure of the first and secondinflatable bladders 17-1, 17-2. The first and second inflatable bladders17-1, 17-2 are inflated to respective first and second target pressuresand the control system 33 outputs first and second control signalsSOUT1, SOUT2 to close the first and second valves 32-1, 32-2 (BLOCK240). The control system 33 monitors the seat occupancy status signalSOCC to determine when the seat assembly 2 is occupied (BLOCK 245). Independence on the change in the occupancy status of the seat assembly 2,the control system 33 outputs the pressure decrease signal SDEC toreduce the inflation pressure of the first and second inflatablebladders 17-1, 17-2 (BLOCK 250). The control system 33 may optionallyalso identify or predict when the occupant is vacating the seatassembly, for example with reference to the seat occupancy sensor 25. Independence on identifying that the occupant is vacating the seatassembly 2, the control system 33 generates the pressure increase signalSINC (BLOCK 255). The process repeats until the control system 33 isdeactivated (BLOCK 260).

The control system 33 may be configured to selectively to inhibitgeneration of one or both of the pressure increase signal SINC and thepressure decrease signal SDEC. For example, the control system 33 mayinhibit generation of one or both of the signals if a child seat isdisposed on the seat assembly 2. The control system 33 may, for example,utilise the seat occupancy sensor 25 to detect the presence or absenceof a child seat. Alternatively, or in addition, a sensor may be providedto determine when a fastening mechanism in the seat assembly 2 isactuated to secure a child seat.

The second inflatable bladder 17-2 shown in FIG. 3 comprises a pluralityof second tubular members 19-2 extending in a longitudinal direction. Ina variant, the second inflatable bladder 17-2 may comprise one or moretubular members 19-2 which extend in a transverse direction. Thisarrangement is illustrated in FIGS. 7 and 8 . A perspective view of thecompressible insert 15 with the insert 16 omitted is shown in FIG. 9 .The control system 33 can be configured to vary the inflation pressureof the first and second inflatable bladders 17-1, 17-2 to provide acontrol function to provide an anti-fatigue (massage) function for aseat occupant. In particular, the inflation pressure of each of thefirst and second inflatable bladders 17-1, 17-2 can be increased anddecreased sequentially. By alternating the inflation and deflation ofthe first and second inflatable bladders 17-1, 17-2 out of phase witheach other, the seat cushion 1 induces a pitching hip motion for anoccupant of the seat assembly 2. The seat cushion 1 can be modified alsoto provide a rolling hip motion for the occupant. The anti-fatiguefunction provides an oscillation cycle which may provide longer-termcomfort and may mitigate the effects of back discomfort, via oscillationof the spine and surrounding muscular tissue. At least in certainembodiments, the anti-fatigue function may induce a rhythmic motion ofthe hips and/or spine of the occupant which is representative of themotion occurring when a person is walking. The oscillation cycle could,for example, have an operating frequency of 20 to 100 cycles per minute,for example 50 cycles per minute. It is believed that this may enhancespinal lubrication and/or increase blood flow compared to a staticposture.

In a further embodiment shown in FIG. 12 , the seat cushion 1 comprisesfirst, second, third and fourth inflatable bladders 17-1, 17-2, 17-3,17-4. The control system 33 is configured to control the inflationpressure of each of the first, second, third and fourth inflatablebladders 17-1, 17-2, 17-3, 17-4 to provide a pitching hip motion and/ora rolling hip motion. The first and second inflatable bladders 17-1,17-2 are disposed on a first side of the seat cushion 1; and the thirdand fourth inflatable bladders 17-3, 17-4 are disposed on a first sideof the seat cushion 1. By alternating between inflation of one or moreof the inflatable bladders 17-1, 17-2, 17-3, 17-4 on the first andsecond sides, the control system can induce the rolling hip motion.Alternatively, or in addition, alternating between inflation of one ormore of the inflatable bladders 17-1, 17-2, 17-3, 17-4 at the front andback of the seat cushion 1, the control system 2 can induce the pitchinghip motion.

By way of example, the control system 33 may be configured to implementa control function comprising first and second operating cycles. Thefirst operating cycle comprises inflating and deflating at least one ofthe first and second inflatable bladders 17-1, 17-2. The secondoperating cycle comprises inflating and deflating at least one of thethird and fourth inflatable bladders 17-3, 17-4. The control system 33controls the first and second cycles to induce a cyclical motion about alongitudinal axis X. This cyclical motion may induce a rolling motion ofthe hips of a seat occupant. Alternatively, or in addition, the controlsystem 33 may be configured to implement a third operating cyclecomprising inflating and deflating at least one the first and thirdinflatable bladders 17-1, 17-3; and a fourth cycle comprising inflatingand deflating at least one of the second and fourth inflatable bladders17-2, 17-4. The control system 33 controls the third and fourth cyclesto induce a cyclical motion about a transverse axis Y. This cyclicalmotion may induce a pitching motion of the hips of a seat occupant.

It will be understood that the seat cushion 1 could be modified tocombine the second and fourth inflatable bladders 17-2, 17-4 such thatthe seat cushion 1 consists of three inflatable bladders 17-1, 17-2,17-3. In a further variant, the seat cushion 1 may comprise more thanfour (4) inflatable bladders 17-1, 17-2, 17-3, 17-4. In a furthervariant, the at least one inflatable bladder 17-n may be disposed in theseating region of the seat cushion 1.

The control system 33 comprises one or more controllers 34. It is to beunderstood that the or each controller 34 can comprise a control unit orcomputational device having one or more electronic processors (e.g., amicroprocessor, a microcontroller, an application specific integratedcircuit (ASIC), etc.), and may comprise a single control unit orcomputational device, or alternatively different functions of the oreach controller 34 may be embodied in, or hosted in, different controlunits or computational devices. As used herein, the term “controller,”“control unit,” or “computational device” will be understood to includea single controller, control unit, or computational device, and aplurality of controllers, control units, or computational devicescollectively operating to provide the required control functionality. Aset of instructions could be provided which, when executed, cause thecontroller 34 to implement the control techniques described herein(including some or all of the functionality required for the methoddescribed herein). The set of instructions could be embedded in said oneor more electronic processors of the controller 34; or alternatively,the set of instructions could be provided as software to be executed inthe controller 34. A first controller or control unit may be implementedin software run on one or more processors. One or more other controllersor control units may be implemented in software run on one or moreprocessors, optionally the same one or more processors as the firstcontroller or control unit. Other arrangements are also useful.

In the example illustrated in FIG. 13 , the or each controller 34comprises at least one electronic processor 35 having one or moreelectrical input(s) 36 for receiving one or more input signals SIN-n andone or more electrical output(s) 37 for outputting one or more outputsignals SOUT-n. The or each controller 34 further comprises at least onememory device 38 electrically coupled to the at least one electronicprocessor 35 and having instructions 39 stored therein. The at least oneelectronic processor 35 is configured to access the at least one memorydevice 38 and execute the instructions 39 thereon so as to perform themethod(s) described herein.

The, or each, electronic processor 35 may comprise any suitableelectronic processor (e.g., a microprocessor, a microcontroller, anASIC, etc.) that is configured to execute electronic instructions. The,or each, electronic memory device 38 may comprise any suitable memorydevice and may store a variety of data, information 39, thresholdvalue(s), lookup tables or other data structures, and/or instructionstherein or thereon. In an embodiment, the memory device 38 hasinformation and instructions for software, firmware, programs,algorithms, scripts, applications, etc. stored therein or thereon thatmay govern all or part of the methodology described herein. Theprocessor, or each, electronic processor 35 may access the memory device38 and execute and/or use that or those instructions and information tocarry out or perform some or all of the functionality and methodologydescribe herein.

The at least one memory device 38 may comprise a computer-readablestorage medium (e.g. a non-transitory or non-transient storage medium)that may comprise any mechanism for storing information in a formreadable by a machine or electronic processors/computational devices,including, without limitation: a magnetic storage medium (e.g. floppydiskette); optical storage medium (e.g. CD-ROM); magneto optical storagemedium; read only memory (ROM); random access memory (RAM); erasableprogrammable memory (e.g. EPROM ad EEPROM); flash memory; or electricalor other types of medium for storing such information/instructions.

Example controllers 34 have been described comprising at least oneelectronic processor 35 configured to execute electronic instructionsstored within at least one memory device 38, which when executed causesthe electronic processor(s) 34 to carry out the method as hereinbeforedescribed. However, it is contemplated that the present invention is notlimited to being implemented by way of programmable processing devices,and that at least some of, and in some embodiments all of, thefunctionality and or method steps of the present invention may equallybe implemented by way of non-programmable hardware, such as by way ofnon-programmable ASIC, Boolean logic circuitry, etc.

It will be appreciated that various changes and modifications can bemade to the present invention without departing from the scope of thepresent application. The inflatable bladders 17-n have been describedherein as forming part of the same insert 16. It will be understood thatmore than one inert 16 may be disposed in the compressible member 15.Two or more inserts 16 may be incorporated into the compressible member15. The inserts 16 may each comprise one or more inflatable bladders17-n.

The seat cushion 1 could be moulded in the mould cavity 51 when the oreach inflatable bladder 17-n is inflated. The pre-inflation of the oreach inflatable bladder 17-n enables formation of the chamber(s) 21during the moulding process.

The present invention has been described with particular reference tothe first seat cover 11 provided on the seat base 3. It will beunderstood that the present invention may also be applied to other partsof the seat assembly 2. For example, one or more inflatable bladders maybe provided in the seat back 4. The control system 33 may be configuredselectively to increase or decrease the inflation pressure in accordancewith the method(s) described herein. Sag of the seat cover on the seatback 4 may be reduced. The seat assembly 2 may comprise one or more sidebolsters, for example provided on the seat base 3 or the seat back 4.One or more inflatable bladder may be provided in each side bolster. Thecontrol system 33 may be configured selectively to increase or decreasethe inflation pressure in accordance with the method(s) describedherein. Sag of the seat cover on the seat back 4 may be reduced.

As outlined above, the seating assembly 2 in certain embodiments may beselectively configurable in a deployed condition and a stowed conditionin the vehicle V. The control system 33 may optionally be configured todetect whether the seating assembly 2 is in the deployed condition or inthe stowed condition. The control system 33 can be configured to inhibitincreases in the pressure of the one or more inflatable bladders 19-n ifthe seat assembly is in the stowed condition. The control system 33 canbe configured to detect a change from a stowed condition to a deployedcondition; and/or from a deployed condition to a stowed condition. Thecontrol system 33 can be configured to increase the pressure of the oneor more inflatable bladders 19-n upon detecting a change in thecondition of the seat assembly from the stowed condition to the deployedcondition. The pressure of the one or more inflatable bladders 19-n maybe increased once the seat assembly 2 is in the deployed condition orduring the re-configuration of the seat assembly 2 to the deployedcondition. The control system 33 can be configured to decrease thepressure of the one or more inflatable bladders 19-n upon detecting achange in the condition of the seat assembly from the deployed conditionto the stowed condition. The pressure of the one or more inflatablebladders 19-n may be decreased once the seat assembly 2 is in the stowedcondition or as the seat assembly 2 is re-configured to the stowedcondition.

1. A control system for controlling inflatable bladders disposed in aseat cushion, the seat cushion comprising at least first and secondinflatable bladders, the first and second inflatable bladders beinginflatable independently of each other, the control system beingconfigured to: alternately inflate and deflate the first and secondinflatable bladders to induce a rolling hip motion and/or a pitching hipmotion of an occupant of the seat cushion.
 2. The control systemaccording to claim 1, configured to inflate the first inflatable bladderas the second inflatable bladder is deflated; and deflate the firstinflatable bladder as the second inflatable bladder is inflated.
 3. Thecontrol system according to claim 1, configured such that the inducedrolling hip motion and/or the pitching hip motion have a frequency whichapproximates the cadence of a person walking.
 4. The control systemaccording to claim 3, wherein the frequency is 100 steps per minute. 5.The control system according claim 1, wherein the inflation anddeflation of each inflatable bladder represents one operating cycle, andwherein the control system is configured such that the first and secondinflatable bladders each perform in the range of 20 to 100 operatingcycles per minute or 30 to 70 operating cycles per minute.
 6. A seatassembly comprising a seat cushion and a control system; wherein theseat cushion comprises at least first and second inflatable bladders,the first and second inflatable bladders being inflatable independentlyof each other; and wherein the control system is configured toalternately inflate and deflate the first and second inflatable bladdersto induce a rolling hip motion and/or a pitching hip motion of anoccupant of the seat cushion.
 7. The seat assembly according to claim 6,wherein the first and second inflatable bladders are disposed onopposing sides of the seat cushion.
 8. The seat assembly according toclaim 6, wherein the inflatable bladders are disposed in front and rearpositions respectively.
 9. The seat assembly according to claim 6,wherein the first inflatable bladder is configured to be inflated as thesecond inflatable bladder is deflated; and the first inflatable bladderis configured to be deflated as the second inflatable bladder isinflated.
 10. A method of controlling inflatable bladders disposed in aseat cushion to provide an anti-fatigue function, the method comprising:selectively inflating and deflating at least first and second inflatablebladders disposed in the seat cushion to induce a rolling hip motionand/or a pitching hip motion of an occupant of the seat cushion.
 11. Themethod according to claim 10, comprising inflating the first inflatablebladder as the second inflatable bladder is deflated; and deflating thefirst inflatable bladder as the second inflatable bladder is inflated.12. The method according to claim 10, comprising inflating and deflatingeach of the first and second inflatable bladders 20 to 100 times perminute, or 30 to 70 times per minute.
 13. A vehicle comprising thecontrol system according to claim
 1. 14. A vehicle comprising thevehicle seat assembly according to claim
 6. 15. A non-transitorycomputer-readable medium having stored thereon software that, whenexecuted, is arranged to perform the method according to claim 10.